A cold, threatening chill went down their spine just before half past 10 on Saturday night. Suddenly, unexpectedly, fear gripped. Canguelo or cagómetro, the heebie-jeebies, the crappingyourselfometer, the bogeyman ... call it what you like, it was back. Captain Paranoia leapt on to their shoulders and, cackling malevolently, whispered into their ears: you're going to blow it. They'd gone from cruising to crisis in a heartbeat – and their hearts were beating harder than ever, smashing through their sternums. In the Sánchez Pizjuán dugout Tito Villanova was gently, contentedly patting Pep Guardiola on the knee: it's done. Five minutes later, Guardiola was furiously, violently elbowing it into submission. Once, twice, three times. No it's bloody not.

They were both right. Week 37 in La Liga, the penultimate week of the season, the one everyone declared decisive; the one in which, except for third, every significant place was up for grabs, every match kicked off simultaneously, and every fan was as preoccupied with events elsewhere as what was unfolding before their eyes. A week in which the title was in the balance and, high in the Santiago Bernabéu, journalists were watching Real Madrid on the pitch below and Barcelona on the screen in front. Barça were top by a point, plus head to head. Madrid needed them to drop points and this was the match they were counting on: they'd been beaten at Sevilla in October; now, seven months later, it was Barcelona's turn. In fact, they didn't even need to be beaten: a draw would do. The final week hardly counted: Barcelona would beat Valladolid, Madrid would beat Málaga, and Madrid would be champions.

But Madrid weren't champions. Barça were. Not just virtual champions but, for 47 minutes in Seville, actual champions. Three hundred and ninety-five kilometres north, a momentary cheer, an excited murmur, had gone round the Bernabéu just four minutes into Madrid's match with Athletic Bilbao. But, radio earpieces pushed deep into skulls, straining to hear, they had got it wrong – prisoners of anxiety and desire, victims of a quick "¡goal in Sevilla!" and a "¡Gol! ¡Gol! ¡Gol! ¡Gooooooooool!" so drawn out they were left hanging, celebrating a strike they shouldn't have. There was indeed a goal in Sevilla but not a goal for Sevilla. Real Madrid's press officer, sitting on the bench, was urgently trying to get the truth to his players: Sevilla hadn't scored at all, Barcelona had. Leo Messi had brought Maxwell's clever ball down on his chest and thumped a wonderful shot past Andres Palop.

Barça were on their way. It didn't matter that at the Bernabéu Cristiano Ronaldo scored a 21st-minute penalty to make it 1-0 to Real Madrid or even that jelly-headed referee César Muñiz Fernández had left Athletic Bilbao with just 10 men – a decision so bad that Athletic midfielder Carlos Gurpegui complained: "The only thing he didn't do was take the penalty for them." "The fears, the doubts, the drama, the radios, and the hype that surrounded Barça's match and the title were blown away in just four minutes," gloated Sport. Soon, Xavi was producing an implausibly perfect pass for Bojan to make it 2-0 and just after the hour Pedro made it 3-0. It could have been six or seven. Messi and Bojan should have had hat-tricks; Victor Valdés had made only one save. Barcelona were battering Sevilla, on their way to racking up 25 shots and 70% of the possession. And now Sevilla were down to 10 men.

Better still, up at the Bernabéu, Madrid were awful – anxious, stilted, lacking ideas. Fran Yeste had wriggled through their defence to make it 1-1 just before half-time and there was no sign of a way back. By now, the message from Sevilla had got through: after 18 wins in 19 games, all too aware of Barça's score, Madrid appeared finally to give up. The fans had fallen silent, morose. Sevilla 0-3 Barcelona, Real Madrid 1-1 Athletic Bilbao. It was all over. Barcelona's lead was three points plus head-to-head goal difference. Barça were champions.

And then it happened. At 10.23pm, Fredi Kanouté scored to make it 3-1 in Seville. Two minutes later, Luis Fabiano made it 3-2. The ¡¡Gooooooooool! hadn't even come to an end and Madrid fans had barely started celebrating, some still on pause, the cheer hovering at the top of their throats like a plane at the end of the runway, waiting for clearance before taking off, when Gonzalo Higuaín – the man whose increasingly desperate detractors claim never scores important goals – scored an important goal. A massive goal. Suddenly, unbelievably, everything had changed. 3-0 and 1-1 had become 3-2 and 2-1 in five minutes. Soon, 2-1 was 5-1. Barcelona's league was in serious danger of becoming become Madrid's. Four points' difference in the time it takes a radio commentator to say 'goal'. From mathematical champions, Barça were on the verge of finding themselves a point behind; Madrid only needed Sevilla to get one – and there were still 20 minutes to go.

If all the fears, doubts, and drama had been blown away in just four minutes, they came flooding back every bit as fast. Suddenly, Estadio Deportivo's charming cover showing Barcelona's players, trousers down, steaming pile curling up behind them, seemed plausible. AS's crappingyourselfometer was up to a million crapahertz. Here they were in the Sanchez Pizjuán, the ground where they blew the European Cup final against Steaua Bucharest, where they first blew the 2006-07 title thanks to a missed penalty from Ronaldinho, and where they lost their first title of the Pep Guardiola era when Sevilla knocked them out of the Copa del Rey despite getting absolutely murdered. And once again, what should have been a cricket score looked like leaving them walking to the pavilion, empty handed.

There was not a soul in the country who didn't think the same thing: 2007. The year when Real Madrid somehow, God knows how, won the league after Barcelona ridiculously threw it away in the 89th minute of week 34 and in 18 utterly preposterous seconds in week 37, when Raúl Tamudo's late goal took their title and left AS raving about the "fuck of the century". Hell, the second goal even looked like the absurd one they gave away to Betis back then – the entire team turning their backs while a quick free-kick caught them cold. Somehow, Barcelona had contrived to give away that title; now the parallels seemed inescapable. Madrid fans were resuscitated, Barcelona fans were terrified and everyone else was open-mouthed, asking: they couldn't could they? It couldn't happen again could it?

In the end, no it couldn't. As one headline put it: "Barcelona tortured themselves … but won." In truth, they didn't torture themselves as much as might have been expected: if their fans panicked, Barça remained remarkably calm, strikingly in control – although they still had to ride out a couple of scary moments. Not least in the last minute when Kanouté went down in the penalty area under a challenge from Gerard Piqué, whose hands were on the striker's back. It wasn't a penalty but that didn't stop Marca's cover bawling that Barça had been "pushed towards the title" and getting their refereeing expert, Rafa Guerrero, the former linesman whose independence has vanished in the haze, to insist it should have been. More importantly, it didn't stop Barcelona's fans finding their testicles blocking their windpipe.

No wonder they went bonkers on the final whistle. No wonder Laporta was busy leading the songs on the plane, surrounded by sycophants. No wonder fans met Barcelona at the airport with chants of "champions!" It had been so close to going horribly wrong but with a week to go, Barcelona have a one-point lead having overcome the two games where they were expected to drop points – away at Villarreal and away at Sevilla. With a week to go, they only have Valladolid at home left and, never mind the countless lessons from history, as far as the Catalan press are concerned it's already done. They're busy selling the bearskin before hunting the hairy beast, El Mundo Deportivo leading on "It's yours!" and sport chanting: "Sí, Sí, Sí, La Liga ya está aquí". Yes, yes, yes, the league is here.

There's just one problem: Valladolid. Barcelona have won 30 times this season, including twice against their rivals, but Madrid have won 31 and Barcelona still need one more. Without Xavi Hernandez. Valladolid have been beaten just once under new coach Javier Clemente, they're fighting – quite literally – against relegation, and if anyone can play for a 0-0 it's Clemente. "Hopefully, he'll park the bus," grinned the Madrid full-back Álvaro Arbeloa, "or two of them." "We are nearly there," Guardiola said, "but that 'nearly' gets bigger and bigger and bigger with every day. On Monday it will be even bigger, on Tuesday it will be bigger still and by Wednesday it will be immense."

• This is the first time since 1990-91 that La Liga has gone into the final day with the title and all three relegation places still to be decided. Nino's 93rd-minute equaliser gives Tenerife hope, Valladolid might get away with not picking up any points from Barcelona because they got all three from a desperately poor Racing Santander side, and there's still half a chance of a miracle for Xérez after they beat Zaragoza 3-2. Racing coach Miguel-Ángel Portugal complained that Valladolid had "used 'injuries' and little tricks" to win. Zaragoza (despite losing), Almería and Sporting Gijón, on the other hand, all secured survival this weekend. "This is a cheap team," said Sporting coach Manolo Preciado, "but it's one with a pair of bollocks like Spartacus's horse."

Which is something the sides still in trouble will need. Going into the final weekend, Xérez have 33 points while Tenerife, Malaga, Racing and Valladolid all have 36. Malaga play Madrid and need to get as many points as Tenerife, Racing and Xerez. Xérez play Osasuna: they have to win and wait. Should they finish level, in six of eight cases they would survive. No matter what Tenerife do against Valencia, their future depends on other results. And Racing will go down if they can't better the results of Valladolid and Tenerife or Málaga.

• At the other end, Sevilla have a one-point lead over Mallorca as they chase the final Champions League spot. Sevilla go to Almería, Mallorca play Espanyol at home. The loser between them will take a Europa League spot, to be joined by either Getafe or Villarreal. Villarreal have to do better against Zaragoza away than Getafe do against Atlético away. Speaking of Villarreal, Joan Capdevila, the comedy genius whose response to Small Talk's question "what's the first thing you'd do if you became prime minister?" was "resign", was sent off. For cracking jokes. When Joseba Llorente was booked, he asked referee Clos Gómez if the card was for Sergio Busquets. Clos Gómez took offence and showed Capdevila a card, to which he replied: "is that one for Busquets as well?". So Clos got out a second yellow. And they wonder why people think they're a bunch of humourless, miserable sods.

• Zlatan Ibrahimovic, Dmytro Chygrynskiy, Kaká and Karim Benzema all started on the bench this weekend. More than €200m worth of players. No other club in the top flight even has a budget over €100m any more. No wonder Madrid and Barcelona are walking this league.

• Filipe Luis returned to action for Deportivo well ahead of schedule after a broken ankle that was expected to keep him out until next season. He was given a huge ovation from the Depor fans. Well, the Depor fans who made it anyway. There were only 9,000 at Riazor and a banner at one end of the ground read: "After the second half of the season you've put in, this is all you deserve." Twelve weeks later, with Filipe back Depor finally won a game – and it's no coincidence. "We're a different team with him," admitted coach Miguel-Ángel Lotina. Filipe is a left-back.

• Raúl Tamudo bade a tearful farewell to Espanyol, 129 games later. Truly cojonudo, he is arguably the best player in their entire history.